In one aspect the invention relates to a valve member. In another aspect, the invention relates to a solids feeder. In yet another aspect, the invention relates to a process for introducing a particulate material into a tubular member.
The feeding of frangible solids, such as lignite, coal, catalyst, additives and the like into a pneumatic line against a pressure gradient is difficult to accomplish with economy. To maintain the particulate material in motion through the transport line between dumpings of the feeder, the gas flushing the feeder pockets or cavities must be at a high velocity. This generally means that the gas will also be at a high pressure so that the gas will undergo a high pressure drop through the transport line. As the feeder cavity is left pressurized after the particles are ejected its depressurization upon its return to the solids inlet to receive another supply of particulate represents a net energy loss and also causes difficulty in reloading the cavity because the pressurized gas impedes the flow of particulate into the cavity. Feeder operation with a relatively low pressure fluid would mitigate these problems.
A further advantage of using relatively low pressure conveying gas would be reduction of the tendency of the gas to disperse the particulate material as a dilute phase in the transport line upon flushing the cavity. The material could be slugged through the line in dense phase utilizing a relatively low volume of relatively low pressure conveying gas.